As far as I know, I haven't received a warning
I admit I offended someone but I'm gone forever now and why not just chat
Looks like Perma Ban but can be fooled.
https://www.blogseite.com/twitch-account-gesperrt-was-tun/
It is not absolutely necessary to receive an advance warning for a ban. Write to the support and maybe leave it at a 1 week lock.